Method and device for carrying out the automated preparation and characterization of liquid multi-constituent systems

ABSTRACT

A method of automated preparation and characterization of liquid multicomponent systems comprising at least two, preferably three components comprises the automated preparation of a mixture by combining at least two, preferably three components in a vessel, at least one component being metered in an automated fashion into the vessel, and the automated homogenization of the mixture with subsequent automated measuring and evaluation. The apparatus for conducting this method comprises at least one metering station, one closing station, one homogenizing station, one measuring station for determining formulation properties, and one evaluation unit.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a method of and apparatus forautomatedly preparing and characterizing liquid multicomponent systemscomprising at least two, preferably three components.

In the course of the development of liquid formulations, such asdispersions, emulsions or solutions, they are subjected to screeningtests in order to optimize them in respect of their action andstability. For this purpose the formulations are first prepared manuallyand then measured manually. This is a highly complex procedure and hencecostly in terms of time and money, especially if the compositions of theformulations are varied at the same time.

It is an object of the present invention to provide a method andapparatus which permit more rapid and reliable screening of liquidmulticomponent systems where the composition of the formulation isvaried at the same time.

We have found that this object is achieved by a method comprising aplurality of automated steps of preparing and screening themulticomponent systems, and by apparatus having the elements requiredfor this purpose. Although the use of automated methods of discoveringnew materials, catalysts and active substances has recently beensummarized anew—see, for example, B. Jandeleit, D. J. Schäfer, T. S.Powers, H. W. Turner, W. H. Weinberg, Angewandte Chemie Int. Ed.English, 1999, 38, 2494 to 2523 or E. W. McFarland, W. H. and Weinberg,Tibtech, 1999, 17, 107 to 115, the use of automated methods of screeningliquid formulations is not known.

The invention accordingly provides a method of automatedly preparing andcharacterizing at least one liquid multicomponent system comprising atleast two, preferably three components, said method comprising at leastthe following steps:

a) automated preparation of a mixture by combining at least two,preferably three components in a vessel, at least one component beingmetered into the vessel in an automated fashion;

b) automated homogenization of the mixture obtained in step a) to givethe liquid multicomponent system;

c) automated measurement of the liquid multicomponent system; and

d) automated evaluation.

The invention additionally provides apparatus for automatedly preparingand characterizing at least one liquid multicomponent system comprisingat least two, preferably three components, said apparatus comprising atleast the following elements:

(A) a metering station;

(B) a closing station;

(C) a homogenizing station;

(D) a measuring station for determining formulation properties; and

(E) an evaluating unit.

The invention further provides for the use of the method of theinvention or apparatus of the invention for the automated preparationand characterization of at least one liquid multicomponent systemcomprising at least two, preferably three components. Preferredembodiments of the invention are set out in the description, theexamples, the FIGURE, and the dependent claims.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows inventively preferred apparatus for automatic screening ofliquid multicomponent formulations.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the invention, the liquid multicomponent systemcomprises at least two, preferably three components. The number ofcomponents depends on the formulation in question. Advantageously thereare from 3 to 10, in particular from 4 to 8, components present,although there may also be more or else, in the case of pigmentdispersions, fewer. Said at least three components preferably compriseat least (1) one liquid, at least (2) one solid or liquid substancewhich is insoluble in the liquid, and at least (3) one surface-activesubstance. Substance insoluble in the liquid means here that thesubstance dissolves in the liquid either not at all or at most to anextent of up to 10% by weight. Normally, the multicomponent system is inthe form of a dispersion, emulsion, liquid multiphase system, orsolution.

In one preferred embodiment of the present invention the multicomponentsystem is in the form of a dispersion, in particular a pigmentdispersion.

In accordance with the state of the art, chromatic pigments in paintsare characterized by manual weighed introduction of pigment, basevarnish, grinding media, and additives, where appropriate, followed bydispersing of the pigments using a ballmill or a dispersing unit. Inorder to determine the performance properties of the pigments thepigment dispersions are applied manually, which is very complicated andhence costly in terms of time and money. The transparency of transparentpigments can be assessed by means of non-hiding drawdowns overblack/white contrast substrates or by hiding drawdowns of a TiO₂ orcarbon black blend and rubout.

The color strength and also the transparency, scattering power, hueangle, chroma, lightness, and/or hiding power are likewise determinedfrom the TiO₂ blend. Generally speaking, reflection spectra of themanually applied coating films are measured, as described, for instance,in H. G. Völz, Industrielle Farbprüfung [Industrial color testing], VCHWeinheim, 1990.

An optimized coating formulation or pigment formulation has to date beenobtained only by means of a large number of time-consuming and costlytest runs. It remains unclear, however, whether the optimum ultimatelyfound is an absolute optimum or a local optimum, since systematic andparallel investigation of the sphere of parameters in question isimpossible owing to the far-too-large complexity involved.

The paints sector knows of shade elaboration apparatus which isautomated for production purposes but in which, rather than pigmentsbeing dispersed, pigment-containing pastes are merely mixed, asdescribed, for instance, in R. Huhn, Farbe und Lack, 1999, 9, 102 to104.

The use of automated methods of discovering new materials, catalysts,and active substances has recently been summarized anew—see, forexample, B. Jandeleit, D. J. Schaefer, T. S. Powers, H. W. Turner, W. H.Weinberg, Angewandte Chemie Int. Ed. Engl., 1999, 38, 2494 to 2523 or E.W. McFarland, W. H. Weinberg, Tibtech, 1999, 17, 107 to 115.

There is to date no method which allows the performance properties ofthe coloristics and rheology of dispersed pigments in fluid media to bedetected in an automated fashion.

It is a further object of the present invention, then, to provide amethod and apparatus by means of which a multiplicity of dispersions,especially pigment dispersions, preferably simultaneously, can beformulated and characterized in an automated fashion, in particular withthe aim of characterizing their coloristics and rheology.

We have found that this object is achieved by the method of theinvention, in which the automated preparation of the mixture in step (a)takes place by automated weighed introduction of at least one pigmentand at least one varnish into at least one vessel and the automatedhomogenization in step (b) takes place by automated shaking, to give apigment dispersion, and the automated measurement in step (c) takesplace by colorimetry, the following steps additionally being carriedout:

automated closing prior to the automated shaking in step (b),

automated opening of said at least one vessel and automated withdrawalof a defined amount of the pigment dispersion prior to the automatedmeasurement in step (c),

where appropriate, automated homogeneous mixing of the defined amount ofthe pigment dispersion with a white/black paste.

We have found, furthermore, that this object is achieved by theapparatus of the invention, in which the measuring station (D) is acolorimeter and the apparatus additionally includes at least thefollowing elements:

a weighing station upstream of the metering station (A),

a dispersing station downstream of the closing station (B),

a withdrawing station, in particular a pipetting station, downstream ofthe dispersing station,

a further closing station downstream of the withdrawing station.

In one preferred embodiment of the method of preparing a liquidmulticomponent system from at least three components, at least (1) oneliquid, at least (2) one solid or liquid substance which is insoluble inthe liquid, and at least (3) one surface-active substance, the liquid(1) advantageously comprises a solvent, especially water and/or anorganic solvent which may be polar or apolar, examples being alcoholssuch as ethanol and methanol, polyhydric alcohols such as glycerol orpolyols, organic solvents such as xylene, toluene, ethyl acetate,tetrahydrofuran, rapeseed oil methyl ester, paraffins and/or hydrocarbonmixtures. Preferred solvents are water or a water/ethanol mixture. Thesubstance (2) insoluble in the liquid comprises, for example, activepharmaceutical substances, active crop protection substances(herbicides, insecticides, fungicides), nutraceuticals, e.g., vitamins,dyes and/or pigments, for paper, hair or leather, for example; organicsolvents insoluble in (1), examples being those defined above; syntheticor natural waxes, e.g., beeswax, lanolin; synthetic, vegetable or animaloils, e.g., liquid paraffin, rapeseed oil, soybean oil, pine needle oil,rosemary oil, peanut oil, jojoba oil, coconut oil, almond oil, oliveoil, palm oil, castor oil, wheatgerm oil, isopropyl myristate, oressential oils, e.g., dwarf pine oil, lavender oil, rosemary oil, pineneedle oil, eucalyptus oil, peppermint oil, sage oil, bergamot oil,terpentine oil, balm oil, juniper oil, lemon oil, aniseed oil, cardamonoil, camphor oil; polymers insoluble in (1), e.g., active substances incosmetic products (for example, skincare and haircare compositions);specialty chemicals and process chemicals, such as defoamers, waterrepellents for textile and/or leather, paper sizes, corrosioninhibitors, fuel additives, complexing agents, antioxidants, bleaches,enzymes, stabilizers, e.g., UV stabilizers, biocides, block copolymersand random copolymers. The surface-active substance (3) comprises, forexample, solubilizers, surfactants, cosurfactants, hydrotropes,protective colloids such as polyvinylpyrrolidone, generally neutral,cationic, anionic and betainelike dispersants such as polyacrylates,polyacrylic acid and its salts, maleic acid/acrylic acid copolymers,naphthalene-formaldehyde condensates, naphthalenesulfonic acidcondensates, phenolsulfonic acid condensates, neutral and cationizedstarch, polyvinyl alcohol, polyethyleneimine and polyvinylamine, andalso modified products thereof, emulsifiers and/or thickeners;especially anionic, nonionic, cationic or amphoteric surfactants,examples being alkyl polyglycosides, fatty alcohol sulfates, fattyalcohol ether sulfates, alkanesulfonates, fatty alcohol ethoxylates,fatty alcohol alkoxylates, fatty alcohol phosphates, fatty alcohol ethersulfonates, alkyl betaines, sorbitan esters, alkoxylated sorbitanesters, sugar fatty acid esters, fatty acid polyglycerol esters, fattyacid partial glycerides, fatty acid carboxylates, fatty alcoholsulfosuccinates, fatty acid sarcosinates, fatty acid isethionates, fattyacid taurinates, citric esters, silicone polymers, silicone copolymersand/or fatty acid polyglycol esters. The precise composition of themulticomponent system is guided by the field of use. Suitable fields ofuse are specified later on below. A typical dispersion has, for example,the following composition:

Liquid/solid % by weight Substance (melting point) 10 to 20water-insoluble wax melting point 40 to 100° C. 69.8 to 89.6 aqueousprotective liquid colloid (1 to 6%) 0.1 propionic acid liquid 0.1formaldehyde liquid 0.1 to 5   additive X liquid 0.1 to 5   additive Ysolid

The solution of the protective colloid here contains from 1 to 6% byweight of protective colloid, the remainder being water. The additives Xand Y may comprise emulsifiers or dispersants. Another typicalformulation has the following composition: 30% by weight synthetic orvegetable oil, e.g., isopropyl myristate; from 0.1 to 5% by weightemulsifier X; from 0.1 to 5% by weight emulsifer Y; and water as theremainder. Emulsifiers X and Y comprise customary emulsifiers.

Step (a) of the method of the invention comprises automated preparationof a mixture by the combining of at least two, preferably at least threecomponents in a vessel, at least one component being metered in anautomated fashion into the vessel. The vessel appropriately comprises aglass or small bottle with a screw or snap-on closure, preferably with avolume of 1 to 50 ml. There is no restriction here on the way in whichthe components are combined, provided it can be automated. Thecomponents may be combined by introducing one or more componentsinitially, especially one component; automatic metering of one or morecomponents; and/or automatic withdrawal, especially pipetting, of one ormore components from one or more stock containers. In one preferredembodiment of the invention, in step (a) the vessel is empty and atleast one component is metered or pipetted in a defined amount, in anautomated fashion, from a stock container into the empty vessel.

In another particularly preferred embodiment, the components arecombined in the vessel by means of at least one suitable robot. It isalso possible for metering, pipetting and/or dilution steps to becarried out simultaneously in parallel for a plurality of samples.

In the preferred embodiment of the method of the invention for preparingpigment dispersions, the automated preparation of the mixture in step(a) takes place by automated weighed introduction of at least onepigment and at least one varnish into at least one vessel.

The varnish is preferably a solventborne varnish, such as a CAB varnishor an alkyd-melamine varnish, for example, or a waterborne varnish.

Preferably, different pigments are weighed simultaneously, together withsaid at least one varnish, into different vessels which together form agrid.

In another preferred procedure, said at least one pigment is weighedtogether with different varnishes into different vessels which togetherform a grid.

In a further preferred embodiment of the method of preparing pigmentdispersions, said at least one pigment formulation is weighed indifferent metered additions, together with said at least one varnish,into different vessels which together form a grid. With particularpreference, the weighed introduction of the pigment formulations, theunpigmented varnishes, and the grinding media is carried out by means ofat least one suitable robot.

Step (b) comprises automated homogenization of the mixture obtained instep (a), to give the liquid multicomponent system. The homogenizationprocedure is not subject to any restriction, provided an automatedimplementation is possible. Preferably, homogenization takes place bymeans of Ultraturrax, ultrasonic dispersing and/or shaking. Whereshaking is carried out, the vessel sealed in an automated fashion priorto shaking, whereas in the case of ultrasonic dispersion or Ultraturraxthe vessel is sealed in an automated fashion afterward. Sealing ispreferably carried out by means of an appropriate robot. Advantageously,the homogenizing time can be set and changed in an automaticallycontrollable manner. Depending on the homogenization technique, it isalso possible to homogenize a plurality of samples in parallel.

In a further advantageous embodiment of the invention, after step (b)and before step (c), or after step (a) and before step (b), the liquidmulticomponent system is heated and/or cooled in an automated fashion,and if desired may be at the same time mixed, by shaking, for example.In this case, judiciously, the heating or cooling time is settable andcontrollable automatically. It is also possible to heat and/or cool aplurality of samples in parallel. Heating and/or cooling of themulticomponent system to a certain temperature over a defined period oftime allows storage tests to be conducted.

In the preferred embodiment of the method of the invention for preparingpigment dispersions, the automated homogenization in step (b) takesplace by automated shaking to give a pigment dispersion. Prior to theautomated shaking in step (b), said at least one vessel is closed in anautomated fashion.

Said at least one vessel is preferably closed by means of a robot.

Further, preferably, the closed vessel is placed by the robot, forautomated shaking, into a dispersing apparatus, preferably a dispersingunit, with particular preference a Skandex disperser.

Preferably, the dispersing time can be set and changed in anautomatically controllable manner. Depending on the dispersing time,dispersions having different particle size distribution and hence alsodifferent properties are produced, including in particular differentcoloristic properties.

After step (b) has been carried out it is possible to determine thecolloidal stability of the pigment dispersion by way of its rheology.

In step (c), the liquid multicomponent system is subjected to automatedmeasuring. Where the measurement method requires it, the vessel isopened in an automated fashion before step (c) and, if necessary, sealedagain after the end of the measurement, something which in each case maybe carried out by means of a robot. The measuring operation preferablytakes place by means of measurement methods for the automateddetermination of formulation properties, such as stability, viscosity,homogeneity, phase behavior, particle size and particle sizedistribution, overall concentration, solids content, foam behavior,cloud point, concentrations of components, coagulum content, stabilityto hard water, and/or chemical properties, such as the determination offunctional groups of the components. With particular preference,measurement takes place by means of automated viscosity measurements,transmission and reflectance measurements, particle size measurements,acoustic techniques such as techniques, for example, for determiningparticle sizes or the air content, spectroscopic techniques such asRaman, NIR and/or IR spectrometry, and/or image analysis for homogeneitytesting. Most preferably, the measuring takes place by means of at leastone measuring technique selected from automated viscosity measurement,particle size measurement, transmission and/or reflectance measurement,and/or image analysis for homogeneity testing. One investigation or aplurality of investigations in succession may be carried out. Ifrequired, the vessels are opened or sealed between the individualmeasurements. If required, the measurement systems, e.g., the rotationalelement of the rheometer, are automatically cleaned. The viscositymeasurement may be conducted with any viscometer, such as a rotationalviscometer, for example. The homogeneity is determined by way of animage analysis with different lightness levels. In order to determinebodying, sedimentation or concentration gradients of formulations, e.g.,emulsions or dispersions, use is made of transmission or reflectancemeasurements by means of laser beam, which are carried out at differentpoints in the vertical extent of the sample vessel. To determine theturbidity of a solution or microemulsion, transmission or reflectance islikewise measured. The particle size determination is carried out bymeans of light diffraction or light scattering. In one preferredembodiment, measurement comprises bringing the multicomponent system tothe measurement site by means of a robot. Where necessary for ameasuring technique, a sample of the multicomponent system is removed inan automated fashion from the vessel beforehand, preferably by means ofpipetting. Appropriately, the instrument or measuring station used forthe measurement is of modular construction, thereby permitting thedifferent measuring techniques to be exchanged depending on themeasurement task.

In the embodiment of the method of the invention for preparing pigmentdispersions, automated opening of said at least one vessel takes placeprior to the automated measurement in step (c).

The automated opening is preferably likewise performed by means of arobot.

It is followed by automated withdrawal of a defined amount of thepigment dispersion.

Preferably, a suitable robot is used here as well, and withdraws thedesired amount of pigment dispersion by means of a withdrawing unit,preferably a syringe. In order to avoid blockage of the entrance of thesyringe when the color paste or pigment dispersion is being drawn up, itis preferred to insert a disposable syringe to a distance of only 2 to 4mm in each case, the depth of insertion preferably being ensured bymeans of an ultrasonic measurement of the distance.

Preferably, the color paste thus withdrawn is also weighed at the sametime by means of an appropriate balance.

The automated measurement in step (c) takes place, in the method ofpreparing pigment dispersions, by colorimetry.

Colorimetry is preferably performed by recording at least one reflectionspectrum, the measurement of the reflection spectrum taking placepreferably from a distance of 0.1 to 5 cm directly on the liquid pigmentdispersion.

In step (d), the results obtained in step (c) are evaluated.Appropriately, this is done by means of appropriate software, and, ifdesired, the measurement is terminated as soon as at least onemeasurement method characterizes the liquid multicomponent system asbeing unsuitable. The evaluation may also comprise documentation of thecomposition of the formulation, and documentation of the preparationsequence and the measurement results.

In the embodiment of the method of the invention for preparing pigmentdispersions, in which the measuring takes place by colorimetry,preferably by recording at least one reflection spectrum, the reflectionspectrum recorded is evaluated by means of appropriate colorimetrysoftware, preferably determining, inter alia, at least one of thefollowing colorimetric parameters:

dH (δ hue angle), dL (δ lightness), dC (δ chroma), ddE (δ transparency),FAE (color strength/color equivalent).

These parameters allow conclusions to be drawn about the colloidalstability, the size of the particles in dispersion, and thedispersibility.

Preference is given to determining the color equivalent FAE to acomparative sample, and the dispersibility.

The colorimetric values of the comparative sample are preferablylikewise determined by means of the described method of the invention.

In one preferred embodiment of the method of the invention for preparingpigment dispersions, the automated withdrawal of a defined amount of thepigment dispersion prior to measurement in step (c) is followed byautomated homogeneous mixing of the defined amount of the pigmentdispersion with a white/black paste. Homogenization with the white/blackpaste may take place preferably in two different ways.

In one preferred embodiment of the method of the invention for preparingpigment dispersions, a defined white/black paste is discharged to avessel, the color paste or the defined amount of pigment dispersion ismetered in from the syringe, and a homogeneous paste is produced byshaking.

In another preferred embodiment, both the color paste or the definedamount of pigment dispersion and the white/black paste are drawn up indefined amounts in disposable syringes and the two syringes areconnected with a hose which has a bulge section. By back-and-forthmovement of the syringe bulbs, the pastes are homogenized; the effect ofthe syringe bulbs is that the paste which is on the inner walls of thesyringe is completely homogenized. The black/white paste contains from 2to 40% of TiO₂ or carbon black.

In another preferred embodiment of the method of the invention forpreparing pigment dispersions, in step (a), i.e. during the automatedweighing of said at least one pigment and said at least one varnish intoat least one vessel, one or more grinding media are weighed in at thesame time.

As grinding media it is preferred to use, for example, small glassbeads, SAZ beads or steel beads. These grinding media produceperformance-relevant dispersing more effectively and more quickly, sincethey represent a considerable input of mechanical energy into thesystem.

Furthermore, in another preferred embodiment of the method of theinvention for preparing pigment dispersions, the automated weighing ofsaid at least one pigment and said at least one varnish into said atleast one vessel is accompanied by the weighed introduction of at leastone or more additives as well. By means of these additives it ispossible to stabilize the colloidal pigment particles in said at leastone varnish: for example, by the maintenance of a steric distance or byway of corresponding electrical charging.

Possible additives include all surface-active substances, among themsurfactants, polymers, and pigment derivatives. They act as defoamers,deaerators, wetting agents, dispersants and/or as leveling additivesand/or as rheology modifiers.

The invention additionally provides apparatus as defined above. Suitablemetering stations include dosimats, hose pumps and/or metering stationsfor melts having a temperature of up to 300° C. The metered amount maybe controlled or checked by way of a balance. A particularly suitableclosing station is a screw station with lid dispenser. The homogenizingstation preferably comprises an Ultraturrax, an ultrasonic disperser, ashaker/agitator or a mixer. A combination of two or more of thesedevices is also possible. The measuring station preferably comprisesinstruments suitable for determining the abovementioned formulationproperties, an example being colloidal properties of the formulations.Examples of typical measuring stations are rheometers, turbiditymeasuring instruments, measuring instruments for determiningtransmission and/or reflectance, instruments for image analysis, Ramanspectrometers, NIR spectrometers, IR spectrometers and/or particle sizemeasuring instruments. It is also possible to use two or more of saidinstruments. Particular preference is given to an instrument fordetermining rheology properties, an instrument for measuringtransmission and/or reflectance, an instrument for particle sizemeasurement, and/or an instrument for image analysis for homogeneitytesting.

In one preferred embodiment of the invention, the apparatus furthercomprises at least one of the following elements:

(A′) a pipetting station;

(C′) a heating and/or cooling station, with or without mixer and/orshaker; and

(F) a robot.

One further preferred embodiment of the apparatus of the inventionprovides apparatus for automatedly preparing and characterizing at leastone dispersion, in particular at least one pigment dispersion, themeasuring station (D) being a colorimeter and the apparatus additionallyincluding at least the following elements:

a weighing station upstream of the metering station (A),

a dispersing station downstream of the closing station (B),

a withdrawing station, in particular a pipetting station, downstream ofthe dispersing station,

a further closing station downstream of the withdrawing station.

The apparatus of the invention for preparing and characterizing pigmentdispersions preferably further includes at least one of the followingelements:

a metering station for grinding media,

a metering station for solid and/or liquid additives,

a robot,

a metering station for white/black pastes.

The individual elements and/or instruments are preferably arranged inthe following way:

In a weighing station, preferably for pulverulent pigments, and adownstream metering station for grinding media, defined mixtures ofgrinding media and pulverulent pigments are produced. In a downstreammetering station for solid and/or liquid additives it is possible to adddesired additives. In a downstream metering station, preferably forunpigmented base varnishes, a corresponding base varnish is added.

In a downstream closing station, preferably a screwing station, thevessel containing the mixture is closed, preferably by means of anappropriate robot, and is supplied, again preferably by means of arobot, to a dispersing unit, preferably a Skandex disperser. In thedispersing unit, a pigment dispersion is produced by shaking. Preferablyit is possible here for a plurality of vessels, containing differentmixtures and together forming a grid, to be shaken in parallel at thesame time, so producing different pigment dispersions simultaneously.

After a variable dispersing time, which can be set, the vesselscontaining the grinding media and the pigment dispersions are removedfrom the dispersing unit, preferably by means of a robot, and are openedin a suitable withdrawing station. In a corresponding withdrawingstation, in particular a pipetting station, a defined amount of thepigment dispersion is withdrawn from each vessel. In order to preventgrinding media blocking the entry to the syringe while the pigmentdispersion is being drawn up, a disposable syringe is inserted only to adistance of 2 to 4 mm into the millbase. The depth of insertion isensured by means of an ultrasonic measurement of the distance. Thepigment dispersion withdrawn in the pipetting station in this way ispreferably weighed and, in a further preferred embodiment of theinvention, is mixed homogeneously with a defined amount of white pastein order to produce pigment dispersions.

The homogenized pastes are preferably placed in a glass dish by means ofa robot and the hiding layers of the pastes are measured by means of anappropriate colorimeter. Light having a wavelength of from 400 to 700 nmis shone in as flashes of light, at an angle of 45°, each at intervalsof 20 nm. The measurement spot has a diameter of approximately 3 cm.

By mixing with white paste and black paste there become in virtually anylayered hiding formulation of the transparent pigment pastes. In thisway it is possible to determine the transparency.

A reflection spectrum is measured directly on the liquid paste from adistance of from 0.1 to 5 cm. Evaluation is carried out by means ofappropriate colorimetry software, in order to determine the colorimetricparameters dH, dL, dC, ddE, the color equivalent FAE to a comparativesample, and the dispersibility.

In a further preferred embodiment, the evaluating unit (E) comprises atleast one computer for data capture and data evaluation. It is alsopossible to provide a documenting unit.

Preferably, the individual elements and/or instruments of the apparatusof the invention for automated preparation and characterization of atleast one liquid multicomponent system comprising at least two,preferably at least three components are arranged, and the method of theinvention for preparing said liquid multicomponent system is carriedout, in the manner shown in FIG. 1, which shows preferred apparatus forautomatic screening.

As shown in FIG. 1, preferably a robot (1), which is preferablypositioned on a rail, first withdraws small bottles from a store (2),which are then labeled by the labeler (3) so that they can be identifiedby a barcode reader (4). These small bottles may already contain one ormore components or may be empty; preferably they are empty.Advantageously, they have not been sealed. It is then possible by way ofa plurality of metering stations (5), for example, by way of threemetering stations as shown in FIG. 1, to meter into the bottles polymermelts, hot melts, e.g., hot wax; highly viscous substances; solids suchas powders or granules, for example; liquids such as oils, water,surfactants, solutions—of active substances and auxiliaries, forexample—alcohols and/or organic solvents, for example. The receivers andmetering units may be heated. It is also possible to withdraw one ormore components from a stock vessel (not shown) by way of a pipettingstation (6) and to pipette them into the bottle. After the componentshave been combined, the bottle containing the sample may, if required,be sealed in a closing station (7), especially a screwing station withlid dispenser. If required, the bottles may be heated in the heatingstation (8) prior to homogenizing. From said station (8), the bottle isbrought by the robot (1) to the homogenizing units (9). After thehomogenizing the bottles, if still open, are sealed in the closingstation (7). Thereafter, the bottle with the sample may pass to theheating station (8) or to a cooling station (10), preferably withintegrated horizontal shaker and fan, or to both stations in succession.From there, or if no heating or cooling operations are carried out, therobot (1) transfers the bottle with the sample to the screening ormeasuring station (11). In this station the bottles, if necessary, areopened at the screwing station (12) and measured by means of one or moreof the abovementioned measuring instruments. FIG. 1 depicts 3 measuringinstruments (13) symbolically, of which one or more may be employed. Thescreening station (11) also includes storage space (14) for samples. Thesamples may therefore be measured repeatedly at particular timeintervals. The samples may also be removed from the entire unit shown inFIG. 1 and replaced in the unit at any desired later point in time, atstore (2) and/or storage space (14) or at the cooling station (10)and/or the heating station (8), for subsequent renewedtreatment/investigation. For this purpose, the samples may beunambiguously identified by way of their barcode. After the results havebeen evaluated, the samples may be sorted in accordance with qualityfeatures, with the possibility of poor samples being discarded as waste(15) in the screening station (11) or else outside of that station: forexample, discarded as waste (16) as early as after homogenization.Throughout the sequence, the bottle is brought to the desired positionby the robot (1) in each case. The possibility also exists of bringingthe samples to the desired point within the screening station (11)independently of the robot (1), for example, with the aid of a furtherrobot. By this means, samples may be measured and prepared in parallelindependently of one another. Following this sequence, the samples thusprepared and measured may be stored outside the screening station (11),for example, in the heating station (8), before being subsequentlymeasured again. The samples may also be pipetted into different vessels,already containing solutions or solvents, e.g., water (pipetting takingplace by way of pipetting station (6)). The “daughter” samples thusprepared may then again be homogenized and/or heated, if required, andsubsequently measured in the screening station (11).

The present invention further embraces the use of the method of theinvention and apparatus of the invention for automatedly preparing andcharacterizing at least one liquid multicomponent system comprising atleast two, preferably three components.

In one preferred embodiment of the present invention, the presentinvention embraces the use of the method of the invention and apparatusof the invention for automatedly formulating and automatedlycharacterizing at least one pigment, in particular for simultaneouslyautomatedly formulating and automatedly characterizing a plurality ofpigment formulations.

The invention is especially suitable for developing new liquidmulticomponent systems, especially size dispersions and defoameremulsions for papermaking; in the laundry detergent industry for thescreening of hydrotropes (solubilizers) for the production of readilysoluble laundry detergent tablets/compacts and highly concentratedliquid formulations, and also acid or alkaline cleaners which dissolveto give clear, homogeneous solutions; and also for the development ofmicroemulsions; for the development of cosmetic formulations such ascreams, lotions, shampoos, hair conditioners, shaving lotions, anddeodorant formulations, for example; for liquid vitamin formulations,food formulations, active substance formulations in crop protection andpharmacy; for the development of water repellent emulsions, for leatheror textile, for example; for the development of solvent-based orwater-based paints and coatings; and for the development of inkjet inks.Generally speaking, the invention is suitable for the development ofcolloidal and disperse formulations and also of solutions or liquidmultiphase systems. The invention is further suitable for thedevelopment of additives and auxiliaries for formulations, including,for example, for developing new surfactants and specialty surfactantsintended, for example, for the abovementioned formulations.

The present invention makes it possible to prepare and characterize alarge number of liquid formulations in a short time. By means of anintelligent software program, the screening of a plurality of samplesmay be optimized in terms of time, by conducting steps (a) to (c) inparallel on different samples. In other words, while, for example, ameasurement is being carried out on sample 1, sample 2 is homogenized inthe meantime, while the formulation components are simultaneouslymetered into the vessel of sample 3. The software also makes it possiblenot to continue investigating the sample that was originally to beinvestigated with a plurality of measuring instruments as soon as ameasured value characterizes the sample as being unsuitable. Therefore,if a sample which should, for example, be homogeneous is characterizedby the image analysis system as being inhomogeneous, it is possible notto carry out any further measurement on this sample, e.g., no subsequentviscosity measurement. As a result, sample screening is made shorter.Using the invention it is possible, for example, to investigate rapidlythe behavior of new additives and commercially customary surfactants andemulsifiers or auxiliaries in liquid formulations while at the same timevarying the composition of the formulation and so to optimize liquidformulations efficiently and reliably. Whereas, with the procedurecustomary to date, one person could prepare and investigate from 10 to20 formulations a day, it is possible by means of the invention for oneperson to prepare and characterize at least 100 samples a day, with thepossibility of storage of formulations at the same time. This is aforceful demonstration of the economy and utility of the presentinvention.

A preferred embodiment of the present invention, the provision of amethod and apparatus for preparing and characterizing pigmentdispersions, makes it possible simultaneously to formulate a pluralityof different dispersions and to characterize them immediately thereafterwithout a large time delay. Applying the different pigment dispersionsto appropriate carrier materials is no longer necessary: instead, theperformance properties, especially those of the coloristics andrheology, may be detected directly in the fluid media containing thedispersed pigments, in an automated fashion. In this context it ispossible to use solvents, oils or waxes alongside the conventional,unpigmented aqueous and solventborne varnish systems.

Whereas with the at least partly manual procedure which has been thenorm to date for the formulation and characterization of pigmentdispersions it has been possible to investigate only about 10 pigmentdispersions per day, it is possible by means of the present invention toanalyze from about 90 to 100 pigment dispersions per day.

The invention is illustrated by means of the following examples, whichrepresent preferred embodiments but do not restrict the invention. Theexamples show a typical procedure when screening emulsions (example 3)and dispersions (example 1) and also crop protection formulations(example 2) and a solubilizate (example 4).

EXAMPLE 1

Screening of Dispersions

A bottle with a capacity of 10 or 50 ml is taken from the store andlabeled and the barcode is read. Subsequently, highly mobile or viscoussurfactants and/or dispersants and/or organic solutions are metered in.Then, in the sequence indicated, protective colloids are metered in at70° C., water is metered in at 70° C., and wax melt is metered in at 80°C. After heating for 5 minutes, dispersion is carried out in anultrasound unit with a 1-12 mm sonotrode for from 1 to 10 minutes. Thesonotrode is cleaned under hot water and with ultrasound. Thereafter,the bottle has a lid screwed onto it and the sample is cooled to roomtemperature on the shaker table for from 15 to 30 minutes. The samplesare subsequently transferred to the screening station, in which they aredetermined for homogeneity, by means of an image analysis instrument,and viscosity. The samples are subsequently stored. All of theoperations are carried out in an automated fashion.

EXAMPLE 2

Screening of Crop Protection Formulations

A bottle with a capacity of 10 ml is taken from the store by a robot.The barcode is applied adhesively by the automatic labeler and thebarcode is subsequently read. Then 3 ml of water and 3 ml of oleic acidmethyl ester containing a herbicide dissolved to a concentration of 25%by weight are metered in in succession at the metering stations.Subsequently, at the pipetting station, two liquid surfactants arepipetted in, in each case from 0.1 to 1.0 g. The bottle is then sealedwith a screw lid and the contents are homogenized by a shaker.Thereafter the bottle is transferred to the screening station. After 1hour, the sample is checked for homogeneity by means of image analysis.If the sample is homogeneous and displays neitherseparation/sedimentation tendencies nor bodying tendencies, this sampleA is screwed open and together with a new vessel for sample B,containing 30 g of water, is conveyed by the robot to the automaticpipetting unit. In the latter unit, 0.6 g of sample A is withdrawn andpipetted into the vessel of sample B. When this vessel is sealed, thecontents (sample B) are shaken, and the vessel and contents aretransferred to the screening station by the robot. In the screeningstation, the aqueous dilute sample B is investigated for homogeneity bymeans of transmission measurement, at time intervals which are definedin the method sequence. Homogeneous and inhomogeneous samples B aresorted in the sample rack of the screening station according tospecified time-based stability criteria. Optionally, the samples B whichare inhomogeneous on a time basis may also be discarded, so producingspace for further samples if required. All operations are carried out inan automated fashion. In this way, different active substances and/orauxiliaries may be screened rapidly and efficiently.

EXAMPLE 3

Screening of Emulsions

A bottle with a capacity of 50 ml is taken from the store and labeledand the barcode is read. Then oils are metered in andemulsifiers/surfactants are metered in. The sample is homogenized withthe mixer. Then water and, if desired, further surfactants are meteredin. The sample is sealed, the mixture is heated to 80° C., the bottle isopened, and the contents are dispersed in an ultrasound device having a1-12 mm sonotrode for from 1 to 10 min. The bottle is then screwed shutand the sample is cooled on the shaker table and then transferred to thescreening station. There, homogeneity and viscosity are determined.Subsequently, the sample is stored in the heating station at 60° C. for2 hours and again transferred to the screening station for themeasurements. The inhomogeneous samples are subsequently discarded andthe stable samples are stored further. All operations are carried out inan automated fashion.

EXAMPLE 4

Screening of Solubilizates

A bottle with a capacity of 50 ml is taken from the store and labeledand the barcode is read. Then oils are metered in and solubilizers areadded by pipette. The sample is homogenized with the mixer. It is thenheated to 80° C. and water heated to 70° C. is mixed in. The mixture ishomogenized with the mixer, cooled on the shaker table and thentransferred to the screening station. There, the homogeneity andturbidity of the sample are measured. All operations are carried out inan automated fashion, the bottle being opened and closed, respectively,in an automated fashion at the corresponding points. By this means,different solubilizates can be screened rapidly.

EXAMPLE 5

Preparation and Characterization of Pigment Dispersions

A 100 ml glass bottle is provided with a bar code. Then 1.5 g of apulverulent pigment preparation, 20 g of glass beads (diameter: 3 mm)and 15 g of an unpigmented varnish are weighed in. A plurality ofbottles filled in this way are dispersed simultaneously in thedispersing unit. After 15 minutes of dispersing, the bottles are takenfrom the dispersing unit and processed further individually. One bottleis first of all unscrewed. Using a 20 ml disposable syringe, 1.5 g ofthe color pigment dispersion are weighed together with 2.0 g of a 20%TiO₂ dispersion into a 20 ml bottle. The contents of the sealed 20 mlbottle are homogenized by shaking. Following homogenization (3 minutes)the contents of this bottle are poured into a petri dish and areflection spectrum of the dispersion is recorded. The 100 ml bottlesare sealed again and dispersed for another 2 hours. The mixing of thecolor pigment dispersion with the TiO₂ dispersion is repeated and againa reflection spectrum is recorded. All operations are carried out in anautomated fashion.

We claim:
 1. A method of automatedly preparing and characterizing atleast one pigment dispersion comprising at least two components, saidmethod comprising at least the following steps: (a) automatedpreparation of a mixture by automated weighed introduction of at leastone pigment and at least one varnish into at least one vessel; (b)automated homogenization of the mixture obtained in step (a) byautomated shaking to give the pigment dispersion; (c) automatedevaluation by colorimetric measurement of the pigment dispersion, andthe following steps being carried out in addition: automated closingbefore the automated shaking in step (b), automated opening of said atleast one vessel and automated withdrawal of a defined amount of thepigment dispersion prior to the automated measurement in step (c), whereappropriate, automated homogeneous mixing of the defined amount of thepigment dispersion with a white/black paste.
 2. A method as claimed inclaim 1, wherein one or more grinding media are weighed in in step (a).3. A method as claimed in claim 1, wherein one or more additives areweighed in in step (a).
 4. A method as claimed in claim 1, wherein thecolorimetric measurement in step (c) takes place by recording at leastone reflection spectrum or recording with a CCD camera.
 5. A method asclaimed in claim 1, wherein in step (a) the vessel is empty and at leastone component is metered or pipetted in a defined amount, automatedly,from a stock container into the vessel.
 6. A method as claimed in claim1, wherein the evaluation in step (c) takes place by means ofappropriate software.
 7. A method as claimed in claim 1, wherein afterstep (b) and before step (c) the liquid multicomponent system is heatedand/or cooled in an automated fashion, with or without simultaneousmixing.
 8. Apparatus for automatedly preparing and characterizing atleast one pigment dispersion comprising at least two components, saidapparatus comprising at least the following elements: (A) a meteringstation (5); (B) a closing station (7); (C) a homogenizing station (9);(D) a colorimeter (11), and (E) an evaluating unit, said apparatusfurther comprising at least the following elements: a weighing stationupstream of the metering station (A), a dispersing station downstream ofthe closing station (B), a withdrawing station, in particular apipetting station, downstream of the dispersing station, a furtherclosing station (7) downstream of the withdrawing station, and theautomation is carried out by means of a robot.
 9. Apparatus as claimedin claim 8, further comprising at least one of the following elements: ametering station for grinding media, a metering station for solid and/orliquid additives, a robot, a metering station for white/black pastes.10. Apparatus as claimed in claim 8, wherein the evaluating unit (E)comprises at least one computer for data capture and data evaluation.